JP4456499B2 - Work tools - Google Patents

Description

  The present invention relates to a work tool construction technique.

Conventionally, for example, Patent Document 1 below discloses an electric tool configured to drive a tip tool by an electric motor. The electric tool includes a main body part, a tip tool attached to the front end side of the main body part, an electric motor housed in the main body part and driving the front end tool, and a tip end from the grip base end on the main body part side toward the grip front end. It is set as the structure provided with the hand grip (handle part) extended in the elongate shape in the direction which cross | intersects the axial direction of a tool.
JP 2002-254341 A

In the above-mentioned Patent Document 1, there is a possibility of trying to eliminate the burden on the finger of the operator holding the handgrip by devising the cross-sectional shape of the main body portion of each part of the electric tool. In various types of work tools in which an operator grips a handgrip, such as this type of electric tool, further technical exploration for pursuing a reduction in the burden on the fingers of the operator is required. Therefore, the present inventors, when working with this type of work tool, the shape of the finger and palm of the worker holding the hand grip, the stress that the finger and palm exert on the hand grip, the hand grip Various investigations related to the burden on the operator's fingers, such as grip feeling (feeling of fit, sickness, etc.) felt by the gripping worker, were conducted. As a result of the study, the present inventors can reduce the burden on the fingers of the operator by pursuing a particularly optimal hand grip shape, and the operator's hand is hard to get tired and hurts even during long hours of work. They succeeded in finding a handgrip structure that is difficult to be formed.
It is an object of the present invention to provide a technique effective for reducing a burden on an operator's finger in an operation tool configured to perform an operation by gripping a handgrip by an operator.

  In order to achieve the above object, the invention described in each claim is configured. The present invention can be applied to various types of work tools used for screw tightening work, cutting work, cutting work, grinding / polishing work, nailing work, hammering work, drilling work, and the like.

The work tool according to the present invention includes at least a main body portion, a tip tool, a driving means, and a hand grip. The tip tool of the present invention is configured as a tool attached to the tip side of the main body, and is used for screw tightening work, cutting work, cutting work, grinding / polishing work, nailing work, hammering work, drilling work, etc. Used. The drive means of this invention is comprised as a means accommodated in a main-body part, and drives a front-end tool. As a driving means of the present invention, an electric motor that operates with a current supplied from a battery mounted on a tool body or a current supplied from a power source using a power cord, or a driving mechanism that operates with the pressure of air or combustion gas Can be adopted. Accordingly, the “work tool” of the present invention includes a wide range of electric work tools, air-driven and gas-driven work tools. In addition, as a working mode using the working tool of the present invention, a mode in which the work is performed while pressing the tip tool extending in the horizontal direction forward, while a tip tool extending in the vertical direction is pressed upward or downward. There are a form of performing work, a form of performing work while pressing a tip tool extending in an oblique direction upward or downward, and the like.

  The hand grip of the present invention extends in a long shape in the direction intersecting the axial direction of the tip tool from the grip base end on the main body side toward the grip tip, and is gripped by an operator (tool user) by hand. Configured as a gripping part. Therefore, in the present invention, the “hand grip” corresponds to a portion (region) to which the gripping force (grip force) of the hand reaches when the worker grips the work tool by hand.

  In particular, in the hand grip of the present invention, the upper end of the line connecting the tops of the grip side surfaces in the vertical direction is directed toward the rear end side of the grip base end, while the lower end of the line is directed toward the front end side of the grip front end. Thus, it has a configuration extending in an S shape. In this case, when the connection at the top of one grip side surface extends in an S shape, the connection at the top of the other grip side surface is a mirror image of the connection (S shape).

  According to such a configuration, a convex grip portion that is the top of the grip side surface fits into a recess (recessed portion) formed in the palm of an operator who is gripping, realizing a highly fit hand grip structure Is done.

In a further aspect of the power tool of the present invention, the handgrip is connected to connecting the top of the grip side continuously shaped in the vertical direction, the palm of generally emotional line or intelligence line in the grip holding state (both brain line It is the structure extended along. That is, in consideration of the fact that the palm in the grip holding state is formed with a depression (concave part) along the emotional line and the intelligence line, in the present invention, the top part (convex part) on the grip side surface along the depression. Is configured to extend.
According to such a configuration, a hand grip structure with a higher fit is realized in consideration of the shape of the palm of the operator.

The power tool further embodiment of the present invention, the handgrip, as normal at the rear end surface of the grip distal end region of each part of the hand grip, intersects the axis of the tool bit in the grip front Is configured .

  According to such a configuration, the operator can grip the handgrip uniformly with the entire palm, and can perform work with the gripped handgrip pressed uniformly toward the tip of the tool. A hand grip structure that is easy to get tired and hard to hurt during work is realized.

Power tool further embodiment of the present invention includes an electric motor as driving means, a battery that is removably attached to the grip distal end portion of the handgrip to supply current to the electric motor.

  In particular, the battery according to the present invention includes a housing portion that houses one or more cylindrical battery cells, and the housing portion is arranged in a grip outer region below the grip tip portion when the battery is mounted. Yes. As the cylindrical battery cell, a nickel metal hydride battery having a dry battery shape can be used. Conventionally, in the case of using a battery composed of a rated cylindrical battery cell, it has been common to accommodate a part or all of the cylindrical battery cell housing in the housing space in the handgrip. The size of the part becomes an impediment when designing the shape of the hand grip freely. Therefore, the conventional hand grip has a limit in freely designing and changing its shape. Therefore, in the present invention, by arranging the casing portion of the cylindrical battery cell in the grip outer region, the hand grip shape is cylindrical even when using a battery with a rated cylindrical battery cell. A structure that is not affected at all by the shape of the casing portion of the battery cell is used.

  According to such a configuration, the shape of the handgrip is not limited by the casing portion of the cylindrical battery cell, and it is possible to increase the degree of design freedom with respect to the shape of the handgrip. It is effective for realizing a hand grip structure effective for reducing the burden on the body. Such a configuration is particularly effective as a so-called slide-type battery configuration in which a battery attached to the grip tip is slid in a direction crossing the extending direction of the handgrip to perform the attaching / detaching operation.

  As described above, according to the present invention, in a work tool configured to perform work by gripping the handgrip, particularly by devising the shape of the handgrip, the burden on the finger of the worker can be reduced. It became possible to plan.

  Hereinafter, an embodiment of a “work tool” of the present invention will be described with reference to the drawings. This embodiment will be described using an electric (rechargeable) impact driver as an example of a work tool. This impact driver is referred to as a “work tool” or “power tool”.

  The appearance of an impact driver 100 according to an embodiment of the present invention is shown in FIGS. FIG. 1 shows a side view of an impact driver 100 according to an embodiment of the present invention, and FIG. 2 shows a rear view of the impact driver 100 in FIG.

  As shown in FIGS. 1 and 2, the impact driver 100 according to the present embodiment is generally attached to a main body portion 101 that forms an outline of the impact driver 100 and a tip region of the main body portion 101 in a detachable manner. The driver bit 110 for performing various screw tightening operations, the drive motor 120 accommodated in the main body 101, the hand grip 130, and the battery 140 are mainly configured.

The main body 101 includes a motor housing 103 and a gear housing 105. The main body 101 constitutes a “main body” in the present invention. The main body 101 and the hand grip 130 may be collectively referred to as a “main body”.

  An electric drive motor 120 is accommodated in the motor housing 103, and a driver bit 110 protruding (attached) to the distal end side of the gear housing 105 is driven by the drive motor 120. The drive motor 120 corresponds to the “electric motor” in the present invention, and the driver bit 110 as the driven body driven by the drive motor 120 is the “tip tool attached to the distal end side of the main body” in the present invention. Equivalent to.

  In the gear housing 105, although not particularly shown, a speed reduction mechanism that appropriately reduces the rotation of the output shaft of the drive motor 120, a spindle that is rotationally driven by the speed reduction mechanism, and a hammer that is rotationally driven from the spindle as a transmission member. , And an anvil that is rotationally driven by a hammer. The tip of the anvil protrudes from the tip of the gear housing 105, and the driver bit 110 is detachably attached to the protruding tip.

  The handgrip 130 is a grip that is gripped by an operator when working or carrying it, and when the operator grips the work tool with his / her hand, a portion (area) where the gripping force (grip strength) of the hand is applied. ). This hand grip 130 corresponds to the “hand grip” in the present invention. The handgrip 130 according to the present embodiment is configured to extend in a long shape in a direction intersecting the axial direction of the driver bit 110 from the grip base end 130a below the main body 101 (on the main body side) toward the grip front end 130b. It is said. A trigger 131 for turning on a power switch (not shown) of the drive motor 120 is provided at the front of the grip of the hand grip 130. That is, the trigger 131 is operated by the operator to drive or stop the drive motor 120 and corresponds to a “trigger” in the present invention.

  In the present embodiment, the main body 101 including the hand grip 130 has an outer shell portion (casing portion) formed of a hard material (hard synthetic resin material or the like). Further, a buffer portion formed of a soft material (soft synthetic resin material, rubber material, etc.) softer than the hard material is provided. This buffer portion is a member indicated by, for example, a hatched line in FIG. 1, and is configured at least by the side abutting portion 107, the rear end abutting portion 109, the grip front abutting portion 132, the grip rear abutting portion 133, and the connecting portion 134. The side contact portion 107 is a portion formed on both side surfaces of the main body portion 101, and the rear end contact portion 109 is a portion formed on the rear end surface of the main body portion 101. The grip front abutting portion 132 is a portion formed on the front surface and the side surface of the hand grip 130, and the grip rear abutting portion 133 is a portion formed on the rear surface of the hand grip 130. Moreover, the connection part 134 is a site | part which extends the side contact part 107, the grip front contact part 132, and the grip back contact part 133 in connection shape. By providing the buffer portion having such a configuration, it is possible to give a soft grip feeling to an operator who holds the hand grip 130 and performs an operation, and to give a novel impression to the operator in appearance. It becomes possible.

  The battery 140 is detachably attached to the grip front end portion (lower end portion) of the hand grip 130. Although not particularly illustrated, the battery 140 includes a plurality of cylindrical battery cells (storage batteries) as a power source for supplying current to the drive motor 120, and the casing portion is arranged in a state in which the plurality of cylindrical battery cells are arranged in a sideways manner. Is housed in. In addition, it can replace with this structure and can also use the structure accommodated in a housing | casing part in the state which arrange | positioned the one or several cylindrical battery cell in the inverted state. In addition, in the accommodation space in the handgrip 130, various boards and wirings for connecting the drive motor 120 and the battery 140 are accommodated.

Here, FIG. 3 shows a mounted state and a detached state of the battery 140 in the impact driver 100 in FIG. As shown in FIG. 3, in the battery 140 of the present embodiment, a part or the whole of the casing portion that accommodates the cylindrical battery cell does not protrude upward from the upper surface of the battery, and the grip tip 130b is in a battery-mounted state. The casing portion of the cylindrical battery cell is disposed in the grip outer region below the grip tip, that is, the casing portion of the cylindrical battery cell is not accommodated in the accommodating space in the handgrip 130. . The battery 140 corresponds to a “battery” in the present invention. This configuration is a so-called plug-in type in which the casing portion of the cylindrical battery cell protrudes upward from the upper surface of the battery and a part or all of the casing portion of the cylindrical battery cell is accommodated in the accommodation space in the handgrip in the mounted state. This is different from the configuration of a battery of the type called That is, the battery 140 according to the present embodiment has a cylindrical battery cell housing portion disposed in the grip outer region, and is configured so as to be slidable with respect to the battery mounting operation (attachment) and the battery detaching operation (removal). It is configured as a type called a slide type. Therefore, the battery 140 can be detached and attached by sliding the battery 140 as it is along the sliding direction (direction intersecting the axial direction of the driver bit 110) from the attached state.
The battery 140 detached (removed) from the handgrip 130 side can be charged by being attached to a dedicated charger (not shown).

  In the impact driver 100 configured as described above, when the operator grips the hand grip 130 and pulls the trigger 131 to turn on the power switch, the drive motor 120 is energized to drive the speed reduction mechanism, spindle, hammer, anvil. The driver bit 110 is rotationally driven through the screw and the screw tightening operation is performed. Since the operating principle of the impact driver 100 itself belongs to a well-known technical matter, a detailed description of its configuration and operation is omitted for convenience.

  As an operation form using the impact driver 100 of the present embodiment, an operation is performed while pushing the driver bit 110 extending in the horizontal direction forward, and the driver bit 110 extending in the vertical direction is moved upward or downward. A form in which the work is performed while pressing, a form in which the work is performed while pushing the driver bit 110 extending in the oblique direction upward or downward, and the like are assumed.

  Next, a specific configuration and operation of the hand grip 130 according to the present embodiment will be described in detail with reference to FIGS.

  Note that, in the present embodiment that employs the sliding battery 140 as described above, the size of the accommodation space in the handgrip 130 is not limited by the housing portion of the cylindrical battery cell. The structure of the hand grip 130 is effective for increasing the degree of freedom in design. That is, in a work tool to which a plug-in battery is mounted, the shape of the handgrip is affected by the shape of the casing portion of the cylindrical battery cell housed in the housing space in the handgrip. According to the configuration in which the slide type battery is mounted as in the embodiment, the shape of the hand grip is not affected by the shape of the casing portion of the cylindrical battery cell, and the degree of freedom in design with respect to the shape of the hand grip. Will increase. Therefore, the present inventors have made extensive studies on a handgrip shape that makes it possible to reduce the burden on the operator's fingers by making use of the characteristics of this configuration, and that prevents the operator's hand from getting tired and painful even during long-time work. As a result, the following effective hand grip structure has been conceived.

FIG. 4 shows a side view of the hand grip 130 of the present embodiment.
In the hand grip 130 shown in FIG. 4, the first grip region 135 is a region where a webbed portion between the thumb and the index finger in the grip gripping state is located. The second grip region 136 is a region where the middle finger in the grip holding state is located. The third grip region 137 is an intermediate region where the middle finger or the ring finger in the grip gripping state is located. The fourth grip region 138 is a region where the ring finger in the grip holding state is located. The fifth grip region 139 is a region where the little finger in the grip holding state is located. In particular, the region from the second grip region 136 to the fifth grip region 139 is set to a range of 47.0 mm ± 2% from the grip distal end 130b to the grip proximal end 130a as an example.

  Further, regarding the cross-sectional structure of the hand grip 130 in FIG. 4, FIG. 5 shows a cross-sectional structure taken along line AA in FIG. 4, and FIG. 6 shows a cross-sectional structure taken along line BB in FIG. 4 shows a cross-sectional structure taken along line CC in FIG. 4, FIG. 8 shows a cross-sectional structure taken along line DD in FIG. 4, and FIG. 9 shows a cross-sectional structure taken along line EE in FIG. It is. In the present embodiment, each of these cross sections is a surface along the direction in which battery 140 extends in the longitudinal direction.

  As shown in FIG. 5, the cross-sectional structure in the first grip region 135 of the hand grip 130 is configured in an elliptical shape. As an example, the major axis a1 in the front-rear direction of the grip in the cross section is in the range of 53.6 mm ± 2%. The short axis b1 in the left-right direction of the grip is set in a range of 31.2 mm ± 2%.

  As shown in FIG. 6, the cross-sectional structure in the second grip region 136 of the handgrip 130 is configured in an elliptical shape. As an example, the major axis a2 in the front-rear direction of the grip in the cross section is in the range of 46.0 mm ± 2%. The short axis b2 in the left-right direction of the grip is set in a range of 34.5 mm ± 2%.

  As shown in FIG. 7, the cross-sectional structure in the third grip region 137 of the hand grip 130 is configured in an elliptical shape. As an example, the major axis a3 in the front-rear direction of the grip in the cross section is in the range of 45.4 mm ± 2%. The short axis b3 in the left-right direction of the grip is set in a range of 33.7 mm ± 2%.

  As shown in FIG. 8, the cross-sectional structure in the fourth grip region 138 of the handgrip 130 is configured in an elliptical shape. As an example, the major axis a4 in the front-rear direction of the grip in the cross section is in the range of 43.3 mm ± 2%. The short axis b4 in the left-right direction of the grip is set in a range of 32.0 mm ± 2%.

  As shown in FIG. 9, the cross-sectional structure in the fifth grip region 139 of the hand grip 130 is configured in an elliptical shape. As an example, the major axis a5 in the front-rear direction of the grip in the cross section is in the range of 38.7 mm ± 2%. The short axis b5 in the left-right direction of the grip is set in a range of 29.4 mm ± 2%.

As shown in FIGS. 6 to 9, the grip diameter (long diameter and short diameter) of the hand grip 130 according to the present embodiment ranges from the second grip area 136 to the second grip area 136 in the range from the grip tip side. It is the maximum in the third grip region 137. The grip diameter (long diameter and short diameter) is configured to become smaller from the maximum diameter portion toward the grip tip 130b side and to be minimum in the fifth grip region 139. Although not particularly shown, the cross-sectional area and the grip outer diameter in each cross section are substantially the same in the second grip region 136 and the third grip region 137 as in the case of the grip diameter, and become smaller toward the grip tip 130b side. Thus, the fifth grip region 139 is configured to be minimum.
In the present embodiment, as an example, the value of the grip diameter (long diameter and short diameter) related to the cross section along the longitudinal extension direction of the battery 140 has been described, but the grip diameter (long diameter and short diameter) at each grip portion is described. The value of can be appropriately set in consideration of the position and orientation of the cross section, errors, tolerances, and the like.

  In general, when gripping a hand grip, it is possible to effectively use the grip force (grip strength) of the entire palm, especially if the little finger can be gripped strongly (tightly). In consideration of this, in the present embodiment, the grip size (at least the grip diameter) is maximized in the region where the middle finger or ring finger is wound, and is minimized in the region where the little finger is wound. At this time, the second grip region 136 and the third grip region 137 correspond to the “maximum diameter portion” in the present invention, and the fifth grip region 139 corresponds to the “minimum diameter portion” in the present invention. is doing. In the present invention, as in the present embodiment, the position of the maximum diameter portion (region where the grip diameter is maximum) is the maximum cross-sectional area portion (region where the cross-sectional area is maximum) or the maximum outer peripheral length portion (grip). The position of the region having the maximum outer peripheral length may or may not substantially match. Similarly, the position of the minimum diameter portion (region where the grip diameter is minimum) is the minimum cross-sectional area portion (region where the cross-sectional area is minimum) or the minimum outer peripheral length portion (region where the grip outer peripheral length is minimum). It may or may not substantially match the position.

  Further, in the X region shown in FIG. 4, that is, in the grip base end 130 a rather than the second grip region 136, the grip diameter, the grip outer peripheral length, and the grip sectional area are not shown, although the sectional shape is not particularly shown. The grip region 136 is configured to be relatively smaller. That is, when the operator grips the work tool with his / her hand, the portion where the gripping force of the hand is substantially thin is configured as thin → thick → thin as it goes from the grip base end 130a side to the grip front end 130b side. ing.

  FIG. 10 schematically shows the surface shape of the hand grip 130 of the present embodiment.

  The hand grip 130 shown in FIG. 10 is configured such that a normal line L1 at the rear end surface on the grip front end 130b side (a line perpendicular to the tangent line L2 at the rear end surface) intersects the axis of the driver bit 110 in front of the grip. ing. That is, in FIG. 10, the normal line L1 extending linearly to the left obliquely upward intersects the axis (not shown) of the driver bit 110 extending in the substantially horizontal direction in front of the grip. A normal line that intersects with the axis of the driver bit 110 in front of the grip, such as the normal line L1, only needs to be formed in at least a part of the grip tip side region. For example, the normal line may be formed only in the grip tip 130b. Alternatively, a plurality may be formed in a predetermined region from the grip distal end 130b toward the grip proximal end 130a. In the present embodiment, this normal L1 is set based on “human body data analysis” described later.

  Further, in the handgrip 130 shown in FIG. 10, a line that continuously connects the tops on the grip side surfaces in the vertical direction, for example, the top P (B) in the second grip region 136, the top P ( C) A connection line that continuously connects the top portion P (D) in the fourth grip region 138 and the top portion P (E) in the fifth grip region 139 forms a curve L3. When the grip side surface shown in FIG. 10 is viewed, the curve L3 has an S shape so that the upper end of the line is directed toward the rear end side of the grip base end 130a and the lower end of the line is directed toward the front end side of the grip distal end 130b. It is set as the structure extended. In this case, when the connection at the top of one grip side surface extends in an S shape, the connection at the top of the other grip side surface is a mirror image of the connection (S shape). This curve L3 corresponds to the “connection” in the present invention. In the present embodiment, the curve L3 or the extended line L4 extending along the curve L3 is set based on “human body data analysis” described later.

  Further, the hand grip 130 shown in FIG. 10 is configured such that the normal line L7 on the trigger front surface of the trigger 131 (a line perpendicular to the tangent line L8 on the trigger front surface) intersects the axis of the driver bit 110 in front of the grip. Yes. That is, in FIG. 10, the normal line L7 extending linearly obliquely upward to the left intersects the axis of the driver bit 110 (not shown) extending in the substantially horizontal direction in front of the grip. The trigger front surface of the trigger 131 is a contact area of an index finger that is pulled by an operator. A normal line that intersects the axis of the driver bit 110 in front of the grip, such as the normal line L7, may be formed in a part of the front surface of the trigger, or may be formed in a plurality of parts. In the present embodiment, this normal L7 is set based on “human body data analysis” described later.

  The handgrip structure of the handgrip 130 is based on the following human body data analysis, sensory evaluation analysis, dynamic simulation analysis, and the like. The handgrip 130 of the present embodiment can reduce the burden on the operator's fingers, particularly as a result of verification by evaluation using mechanical simulation analysis and sensory evaluation analysis. It was confirmed that the hands were less tired and less painful.

(Human body data analysis)
The present inventors have sampled the shape of the fingers and palms in order to grasp the shape of the fingers and palms of the worker holding the handgrip. The sampling subjects were 30 Japanese adult males 20 to 40 years old. FIG. 11 shows the shapes of fingers and palms when a grip holding state is assumed.

  As a result of the sampling, in FIG. 11, the vertical distance d1 from the lower surface of the hand to the webbed portion was 82 mm on average, and the horizontal distance d2 from the base of the hand to the index finger was 181 mm on average. Further, the extension angle θ1 of the extending line L5 extending along the extended index finger with respect to the horizontal line is 10 ° on average, and the perpendicular of the extending line L6 in which the palm depression (recessed portion) extends in the vertical direction. The extension angle θ2 with respect to the line was 15 ° on average. In addition, the extended line L6 regarding a palm can be prescribed | regulated as a line generally extended along an emotional line or an intelligence line (it is also called a brain line).

  In the present embodiment, based on this sampling result, a handgrip structure is formed in which the normal line L1 at the grip rear end surface related to the grip shape is formed along the extended line L5 related to the palm. As a result, the pressing force acting on the rear end face of the hand grip 130 naturally acts uniformly on the entire hand grip 130.

  Moreover, in this Embodiment, it is set as the hand grip structure in which the extended line L4 (curve L3) in the above-mentioned grip side surface regarding a grip shape is formed along the extended line L6 regarding a palm based on the said sampling result. In other words, in consideration of the fact that the palm in the grip holding state is formed with a depression (recessed portion) along the emotional line and the intelligence line, in the present embodiment, the top (convex) on the grip side surface is formed along the depression. Part) extends, and the top part (convex part) is configured to fit into the depression (recessed part). According to such a configuration, the operator can hold the hand grip 130 uniformly with the entire palm.

  Further, in the present embodiment, based on the sampling result, a handgrip structure is formed in which the normal line L7 on the trigger front surface related to the grip shape is formed along the extended line L5 related to the palm. That is, the position and orientation of the trigger 131 are set based on the extending angle θ1 in FIG. 11, and a structure is used in which the operator can easily pull the trigger 131 with the index finger and easily apply force.

(Sensory evaluation analysis)
The present inventors performed sensory evaluation analysis on various existing hand grips including the hand grip 130 of the present embodiment. The sampling subjects were the same as in the case of the human body data analysis, and the grip feeling (fit feeling, sick feeling, etc.) when each hand grip was actually gripped was tabulated.

  As a result of the aggregation, the sampling target is generally preferred to have a shape with a generally narrow grip diameter, a shape with a narrow grip diameter from middle finger → ring finger → little finger, and a shape in which the entire palm touches the handgrip surface uniformly. It was. The handgrip structure of the handgrip 130 satisfies the above-mentioned shapes preferred by the sampling subject, and the sensory evaluation when the sampling subject actually grips the handgrip highly evaluates the grip feeling. It was to be obtained.

(Mechanical simulation analysis)
As dynamic simulation analysis regarding the handgrip 130 and the comparative example of the present embodiment, the present inventors obtain the grip strength distribution on the surface of the handgrip in each handgrip, and based on this grip strength distribution, each part of the fingers and palm ( The pressure and skin shear stress at the webbed part, the part from the index finger to the little finger, and the palm part) were calculated. As a result, by adopting the hand grip 130 of the present embodiment, it is possible to obtain good values for the pressure and skin shear stress at each part of the finger and palm.

  For example, FIG. 12 shows the distribution of skin shear stress in the webbed portion as a result of the dynamic simulation analysis regarding the handgrip 130 of the present embodiment (Example) and the comparative example. As a comparative example, a hand grip having a shape as indicated by a two-dot chain line in FIG. 12 was used. As shown in FIG. 12, especially regarding the skin shear stress exerted on the handgrip by fingers and palms, the skin shear stress in the embodiment is greatly reduced compared to the comparative example, and the webbed portion is less likely to hurt. It was confirmed.

  As described above, by using the handgrip 130 of the present embodiment, it is possible to reduce the burden on the operator's fingers, and it is easy to grip and is hard to get tired, and the hand (especially the webbed part) hurts even during work. Hand grip structure that is difficult to be realized is realized.

  Specifically, in the present embodiment, the normal line L1 at the rear end surface of the grip tip 130b side region intersects with the axis of the driver bit 110 in front of the grip based on the shape of the palm of the operator. Thus, when the work is performed while moving the hand in the grip holding state to the front of the tool, the pressing force acting on the rear end surface of the handgrip 130 naturally acts uniformly on the entire handgrip 130. Therefore, the operator can work with the gripped handgrip 130 pressed uniformly toward the tool tip side, and a handgrip structure is realized in which the hand is less likely to get tired and hurt even during the work. In particular, the configuration is such that the normal line L1 is formed along the extended line L5 relating to the palm, so that the pressing force when the operator presses the handgrip 130 in the gripping state can be easily transmitted to the axis of the driver bit 110. A hand grip structure is realized. Such a grip structure of the handgrip 130 according to the present embodiment includes the impact driver 100 according to the present embodiment and other work tools that may work over a long period of time while pressing the tip tool in various directions. Is particularly effective.

  Further, in this embodiment, when gripping the hand grip, it is possible to effectively use the grip force (grip strength) of the entire palm, especially if the little finger can be gripped strongly (tightly). The grip size (grip diameter, grip cross-sectional area, grip outer circumference length) decreases from the area where the middle finger or ring finger wraps toward the grip tip, especially in the area where the little finger wraps (grip diameter) , Grip cross-sectional area, grip outer circumference length) are minimized. Thereby, the grip force (grip force) by the entire palm is effectively used, and a hand grip structure that is easy to grip and less fatigued is realized. Regarding the size of the grip (grip diameter, grip cross-sectional area, grip outer circumference length), optimal values may be set as appropriate according to differences in the size of fingers and palms according to race, gender, age, etc. it can. As an example, when considering that the size of fingers and palms of Westerners is generally larger than that of Easterners, in the design for Westerners, the grip size (grip diameter , Grip cross-sectional area, grip outer peripheral length) can be scaled up to about 106 to 110%, preferably about 108% of the size of the grip for orients.

  Further, in the present embodiment, the connection line that continuously connects the tops of the grip side surfaces in the vertical direction is a curve L3 that extends in an S shape along the emotional line or intelligence line of the palm in the grip holding state. By configuring so as to form, a hand grip structure with a high fit in which the top part (convex part) of the grip side surface fits into the dent (recessed part) of the palm is realized.

  Further, in the present embodiment, based on the orientation of the operator's index finger, the normal line L7 on the trigger front surface of the trigger 131 extends along the direction in which the index finger extends when the index finger in the grip holding state is extended. By configuring so as to be formed, a rational structure in which an operator can easily pull the trigger 131 with an index finger and easily apply force is realized.

  Further, in the present embodiment, by adopting the battery 140 in which the casing portion of the cylindrical battery cell is arranged in the grip outer region, it is possible to increase the degree of design freedom with respect to the shape of the hand grip. It is effective to realize a hand grip structure effective for reducing the burden on the finger of the person.

(Other embodiments)
Note that the present invention is not limited to the above embodiment, and various application examples and modification examples based on the present embodiment can be conceived. For example, the following embodiments to which this embodiment is applied can be implemented.

  In the present embodiment described above, a hand grip structure related to the size of the grip (grip diameter, grip cross-sectional area, grip outer peripheral length), a hand grip structure related to the shape (normal line L1) on the rear end face of the grip tip 130b side, Although the hand grip structure related to the shape of the top portion (curve L3) on the grip side surface has been described, in the present invention, it is sufficient that at least one of these hand grip structures is satisfied.

  In the above-described embodiment, the case where the casing portion of the cylindrical battery cell of the battery 140 is arranged in the grip outer region of the handgrip 130 is described. However, in the present invention, the desired handgrip shape is affected. If it is possible to reduce the size of the cylindrical battery cell within a range that does not reach, it is possible to use a configuration in which the housing portion of the cylindrical battery cell is accommodated in the accommodation space in the grip.

  Moreover, in this Embodiment mentioned above, although the impact driver 100 used for a screw fastening operation | work is demonstrated to an example as an example of a working tool, this invention is not limited to the impact driver 100, A cutting operation | work is performed. It can be applied to various work tools used for cutting work, grinding / polishing work, nailing work, hammering work or drilling work. At this time, as for the driving method of the tip tool, a configuration in which the tip tool is driven by a rechargeable or drive motor driven by an AC power source, a configuration in which the tip tool is driven by the pressure of air or gas, etc. are appropriately adopted. Can do. In short, the present invention can be applied to various work tools including a handgrip that is held by an operator during work.

1 is a side view of an impact driver 100 according to an embodiment of the present invention. It is the rear view which looked at the impact driver 100 in FIG. 1 from the right side in the figure. It is a figure which shows the mounting state and removal | desorption state of the battery 140 in the impact driver 100 in FIG. It is a side view of the hand grip 130 of this Embodiment. It is a figure which shows the cross-sectional structure in the AA of the hand grip 130 in FIG. It is a figure which shows the cross-sectional structure in the BB line of the hand grip 130 in FIG. It is a figure which shows the cross-sectional structure in CC line of the hand grip 130 in FIG. It is a figure which shows the cross-section in the DD line | wire of the hand grip 130 in FIG. It is a figure which shows the cross-sectional structure in the EE line | wire of the hand grip 130 in FIG. It is a figure which shows typically the surface shape of the hand grip 130 of this Embodiment. It is a figure which shows the shape of a finger or palm at the time of assuming a grip holding state. It is a figure which shows the result of the dynamic simulation analysis regarding the handgrip 130 of this Embodiment, and a comparative example, Comprising: Distribution of the skin shear stress in a webbed part is shown.

100 Impact driver (work tool)
101 Body 103 Motor housing 105 Gear housing 107 Side contact 109 Rear end contact 110 Driver bit (tip tool)
120 Drive motor 130 Hand grip 130a Grip base end 130b Grip tip 131 Trigger 132 Grip front abutting part 133 Grip rear abutting part 134 Connection part 135 First grip area 136 Second grip area 137 Third grip area 138 Fourth Grip area 139 Fifth grip area 140 Battery

Claims (4)

A main body part, a tip tool attached to the front end side of the main body part, a driving means housed in the main body part for driving the front end tool, and the tip tool from the grip base end on the main body part side toward the grip front end A handgrip extending in a long shape in a direction intersecting the axial direction of
The hand grip is such that the upper end of the wire connecting the tops of the grip side surfaces in a vertical direction is directed to the rear end side of the grip base end, and the lower end of the line is directed to the front end side of the grip front end. A work tool having a configuration extending in an S shape. The work tool according to claim 1 ,
The hand grip has a configuration in which the connection line extends substantially along an emotion line or an intelligence line of a palm in a grip holding state. The work tool according to claim 1 or 2 ,
The hand grip is configured so that a normal line at a rear end surface of a grip tip end side region of each part of the hand grip intersects with an axis of the tip tool in front of the grip. . The work tool according to any one of claims 1 to 3 ,
An electric motor as the driving means, and a battery that is detachably attached to the grip tip of the handgrip to supply current to the electric motor,
The battery includes a housing portion that houses one or more cylindrical battery cells, and the housing portion is arranged in a grip outer region below the grip tip portion in a battery-mounted state. Work tool to do.

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